I am not an expert in XDS but will still put my $0.02 in: Your new ORGX seems to be a reflection of the 2theta. In some other programs, origin is always defined at 2theta=0 and the angular (or linear, to that matter) offset is given as a parameter. I.e. software applies 2theta offset internally. If XDS works the same way, then you are confusing it by feeding in the wrong ORGX. Hope it helps, N.
Ruslan Sanishvili (Nukri), Ph.D. GM/CA-CAT, Bld. 436, D007 Biosciences Division, ANL 9700 S. Cass Ave. Argonne, IL 60439 Tel: (630)252-0665 Fax: (630)252-0667 [EMAIL PROTECTED] -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Jan Abendroth Sent: Friday, July 06, 2007 4:01 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] xds, saturn94 and 2theta Hi xds-experts, I am struggling to get xds running for Rigaku's Saturn94 detector with 2theta offset. Without 2theta offset, the Saturn92 input file from the xds webpage works just fine with the following modifications: NX=2084 NY=2084 QX=0.0451 QY=0.0451 ! modified by JA ORGX= 1024 ORGY= 1024 !Detector origin (pixels). ORGX=NX/2; ORGY=NY/2 For a 2theta offset I additionally modified the following parameters: DIRECTION_OF_DETECTOR_X-AXIS=-0.9848 0.0 -0.1736 ! -cos2theta 0 sin2theta ORGX= 795 ORGY= 1070 !measured in VIEW Here the question, as the indexing according to IDXREF.LP does not pick up a good solution. Sometimes it is close, eg. for solutions with a rather good score two axes ok, one off by several Å, sometimes all cell constants are just a little off (2-3Å for a 50/50/90 Å cell). - is the direction of the detector X-axis defined correctly (I also tried -cos2theta 0 -sin2theta) - how does one define the origin of the detector? a) approximate values for the center of the beam from "VIEW" (using 2084, 2084, 2, 0, l or b) b) the refined beam center values from eg. mosflm, translated into pixels? - any other parameters that need to be changed? - I also tried to use only a few or plenty of images for indexing. I know there are other programs for processing data, however, there are good reasons why I'd like to get this data set integrated with xds. Any ideas would be greatly appreciated! Cheers Jan -- Jan Abendroth University of Washington Institute of Biochemistry 1959 NE Pacific Street, K-426 Box 357742 Seattle, WA-98195 phone: +1-206-616-4510 fax: +1-206-685-7002
